Press with semi-automatic cycle

ABSTRACT

In a press of the type comprising a plurality of platens arranged for relative movement in orthogonal directions, an improvement whereby the press remains in operation, once operation of the press has been initiated by a starting switch and once a predetermined point in the operating cycle has been reached, after the starting switch has been opened.

United States Patent 1191 Madsen et al. 51 Apr. 17, 1973 PRESS WITH SEMI-AUTOMATIC 2,976,656 3/1961 Gardner IOU/DIG, 10 CYCLE 3,146,697 9/1964 Dohm, Jr. et a1 100 53 [75] Inventors: Ditlev P. Madsen, Palos Park; Nor- 3179039 4/1965 chnsninsen "100/232 X man y g both of In 3,327,622 6/1967 Lebovitz ..100/DIG. 10 Assignee: Chemetmn Corporation, Chicago, PrimarjExaminer-Robert L. Bleutge AttorneyNicholas M. Esser [22 Filed: Jul 26,197]

211 Appl. No.: 166,087 ABSTRAQT 7 In a press of the type Comprising a plurality of platens [52] Us Cl 100/53 loo/DIG 10 100/232 arranged for relative movement in orthogonal I Ibo/269 directions, an improvement whereby the press remains 51 Int. Cl. .3301) 15/14 in Operation, eflee Operation of the Press has been [58] Field of Search ..lO0/DIG. 10, 53, itiated y a starting SWitch and enee a predetermined 100/42, 232, 269 R point in the operating cycle. has been reached, after the starting switch has been opened [56] References Cited 6 Claims, 4 Drawing Figures UNITED STATES PATENTS 2,850,966 9/1958 Dohm, Jr ..100/D1G. 10

l l i 1 1 1 i 1 2 3,? J6 i 9 1a 141 1 l 1 a2 Patented April 17, 1973 I Sheets-Sheet 2 [J6 /k36 O A m L W G m NH O Fk m 3;? z, .2 M /f I. M

14 mum 1 34 70 I 42 4 4i! STOP sTART 42a i A A HYDRAULIC 44 f PUMP MoToR ,L J8 J4! 414' 3 \7 6f? 66 64 66' 44-4 /T- *(-7H-.OIL COOLER MANUAL AUTOMATIC MOTOR 200 2041 44L AUTOMATIC OPERATION 206' I CY 44 6 v C CLE IN I EMERGENC 2/! 216 AUTOMATIC STOP g g ,iffi r I d AUTOMATIC 4 4 w-zl% -T -H- .C ROL ,6@ 2/0 920 PYRESSING 44 6{ 13 CYCLE i 44 $7 DUMP VALVE END 44L]! K PRESSURE V HIOLD Patented April 17, 1973 3 Sheets-Sheet 5 OEIZOQ 1.5

BACKGROUND OF THE INVENTION This invention pertains generally to an improvement in a press of the type comprising a plurality of platens arranged for relative movement in orthogonal direction. This invention has particular utility in a bacon press of the type described below.

An example of such a press, as used in pressing slabs of bacon, is the ANCO No. l l 1 1 Bacon Press manufactured and sold by The Allbright-Nell Co., Division of Chemetron Corporation, Chicago, Ill. Certain features of the ANCO No. 1 l l 1 Bacon Press are described in U. 8. Pat. No. 3,179,039.

Other generally similar bacon presses are described in U. S. Pat. Nos. 2,850,966 and 3,146,697. Still other generally similar presses and other presses of the type comprising a plurality of platens arranged for relative movement in orthogonal directions are known in the art.

In the example of the ANCO No. l 1 l 1 Bacon Press, bottom, top, end and side platens are arranged for relative movement in orthogonal directions to produce a substantially rectangular pressed slab of bacon. The operating cycle of the press is initiated by means of a starting switch which must remain actuated throughout the operating cycle of the press. For the safety of the operator, the starting switch may be actuated only by actuation of a pair of spaced levers, and the operator must use both of his hands to actuate the levers and must actuate both levers simultaneously in order to ac tuate the starting switch. In other presses, a pair of spaced buttons or the like may be provided in place of such levers.

In such a press, because the operator must actuate the levers or buttons throughout the operating cycle of the press, he is not free to perform any other tasks until after the operating cycle of the press has been completed. Thus, there has been found to be a need for improvements in such a press to free the operator from having to actuate the levers or buttons during a part, including the end, of the operating cycle of the press.

SUMMARY OF THE INVENTION It is the principal object of this invention to provide improvements in a press of the type comprising a plurality of platens arranged for relative movement in orthogonal directions. It is a more particular object of this invention to provide improvements in such a press whereby the press remains in operation, once operation of the press has been initiated by means of a starting switch and once a predetermined point in the operating cycle has been reached, after the starting switch has been opened.

As mentioned, such a press may be constructed to require each ofa pair ofspaced levers to be held by one hand of an operator to actuate the starting switch. In accordance with this invention, once operation of the press has been initiated by means of the starting switch and once a predetermined point in the operating cycle has been reached, the operator is freed from having to hold the levers during the remainder of the operating cycle of the press.

As contemplated by this invention, the operator of a press so constructed may be required to hold the levers until after the platens have moved to positions where they effectively block access from the exterior to the pressing chamber formed by the platens. In the remainder of the operating cycle of the press, there is little likelihood of an accidental injury of the type sought to be prevented by requiring the operator to use both of his hands in initiating operation of the press.

These and other objects, features and advantages of this invention should be apparent from the following description, with reference to the accompanying drawings, ofa preferred embodiment of this invention.

BRIEF DESCRIPTION OF Til-IE DRAWINGS In the drawings:

FIG. 1 is a fragmentary perspective view of a bacon press of the type in which the improvement of this invention has been made and FIG. la is a detail thereof;

FIG. 2 is a schematic diagram of the electrical circuitry of the bacon press of FIG. 1;. and

FIG. 3 is a semi-diagrammatic view of the hydraulic circuitry and related switching elements of the bacon press of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, there is shown a bacon press 10 of the type having a pressing chamber 12 provided by a bottom platen 14, a top platen 16, end platens 18 and 20 respectively, and side platens, 22 and 24 respectively. The platens are flat and rigid and are arranged for relative movement in orthogonal directions to produce a substantially rectangular pressed slab of bacon from an irregularly spaced belly of bacon placed into the pressing chamber 12. As described in further detail below, the press 10 is hydraulically operated, and the platens operate in a controlled sequence. Optionally, the press 10 may include an expandable diaphragm (not shown) of the type described in U. S. Pat. No. 3,179,039. I

In the press 10, the bottom platen l4 and the end platen 18 are fixed relative to the other platens. In an initial condition of the press 10, the top platen I6 is raised relative to the bottom platen 14, the end platen 20 is removed relative to the end platen 18, the side platen 22 is withdrawn relative to the side platen 24, and the side platen 22, which is of the disappearing bar type, is lowered to facilitate loading and unloading of the pressing chamber 12.

As shown primarily in FIG. 2, the press 10 comprises a conventional hydraulic fluid pump 30 (FIG. 3) driven by a conventional 460 volt three-phase Hz electrical motor 32 preferably designed to develop 15 horsepower at 1,200 r.p.m. The press further comprises a conventional fan (not shown) arranged to cool the hydraulic fluid and driven by a conventional 460 volt three-phase 60H2 electrical motor 34 preferably designed to develop 0.25 horsepower at 1,725 r.p.m. The motor 32 is powered by means of a conventional fused three-phasenetwork 36 connected to a source (not shown) of electrical power through a fused switch 38. The motor 34 is powered by means of a similar network 40 connected to the network 36 as shown. A conventional single-phase transformer 42 is connected to the network 36 and is arranged to step down the voltage to l 15 volts to power the control circuit network indicated generally at 44. For clarity of illustration, the

various elements of the control circuit network 44 have been grouped respectively at lines 44-1 through 44-11 of FIG. 2.

Lines 44-1 through 44-4 and lines 44-8 through 44- pertain to manual operation of the press 10 in accordance with teachings known to the prior art. These lines are described in the paragraphs immediately following.

Line 44-1 comprises the low-voltage side 42a of the transformer 42 and a conventional fuse 46. The lowvoltage side 42a of the transformer 42 is grounded through the chassis (not shown) as indicated at 48.

Line 44-2 comprises a normally closed momentary stop switch 50, a normally opened momentary start switch 52, which is connected in parallel with a pair of contacts 54 of a relay associated with the motor 32 for the hydraulic fluid pump 30, the coil 56 of the same relay, and a series of normally closed circuit breakers 58 designed to be opened in the event of an overload of current through line 44-2. The switch 50 is connected to the low-voltage side 42a of the transformer 42 through the fuse 46. The circuit breakers 58 are grounded through the chassis as indicated at 48. The same relay also has a pair of contacts 60 connected in each line of the network 36 between the network 40 and the motor 32 and arranged to be opened when the coil 56 is deenergized and closed when the coil 56 is energized. When the network 44 is energized through the transformer 42, the coil 56 may be energized by momentary closing of the switch 52. Then, after the switch 52 has been opened, the coil 56 remains energized through the contacts 54, and the coil 56 may be deenergized by momentary opening of the switch 50. Accordingly, the switches 52 and 50 control the operation ofthe hydraulic fluid pump 30.

Line 44-3 comprises a pair of additional contacts 62 of the aforementioned relay associated with the motor 32 for the hydraulic fluid pump 30. The contacts 62 are arranged to be opened when the coil 56 is deenergized and closed when the coil 56 is energized. When the contacts 62 are closed, lines 44-5 through 44-11 are connected to the low-voltage side 42a of the transformer 42 through the fuse 44. When the contacts 62 are opened, lines 44-5 through 44-11 are disconnected therefrom. Thus, the press 10 cannot be operated unless the hydraulic fluid pump 30 is operating.

Lines 44-5 through 44-7 and 44-11 pertain to semiautomatic operation of the press 10. For manual operation of the press 10, these lines are disconnected from the network 44 as described below.

Line 44-4, which is connected in parallel with the coil 56 and the circuit breakers 58, comprises a normally opened temperature-sensitive switch 64 designed v to be closed when the temperature of the hydraulic fluid exceeds a preset temperature, the coil 66 of a relay associated with the motor 34 for the fan, and a series of normally closed circuit breakers 68 designed to be opened in the event of an overload of current through line 44-4. The same relay also has a pair of contacts 70 connected in each line of the network 40 and arranged to be opened when the coil 66 is deenergized and closed when the coil 66 is energized. Accordingly, the switch 64 controls the operation of the fan to cool the hydraulic fluid as the temperature of the hydraulic fluid exceeds a preset temperature.

Line 44-8 comprises a normally opened starting switch 80, which is coupled through a suitable linkage (FIG. la) to a pair of spaced levers 82 (FIG. 1a), and a solenoid 84, which is arranged to be energized through the starting switch 80. As is known, the levers 82 are arranged such that the operator must use both of his hands to actuate the levers and must actuate both levers simultaneously in order to actuate the starting switch 80. The solenoid 84, which forms part of a solenoid valve as described hereinafter, is positionable between a first position and a second position and is arranged to be positioned in the first position when deenergized and in the second position when energized. As described hereinafter, the solenoid 84 must remain energized throughout the pressing portion of the operating cycle of the press 10, and the press 10 returns to the initial condition when the solenoid 84 is deenergized.

Line 44-9 comprises a normally opened switch 86, which is ganged with the starting switch for conjoint opening and closing, and a solenoid 88, which may be energized through the switch 86. The solenoid 88, which forms part of a solenoid valve as described hereinafter, is positionable between a first position and a second position and is arranged to be positioned in the first position when deenerigzed and in the second position when energized.

Line 44-10 comprises a normally closed limit switch connected in parallel with the switch 86. As shown in FIG. 3, the switch 90 is positioned relative to the moving parts associated with the top platen 16 such that the switch 90 is opened when the top platen 16 is raised relative to the bottom platen 14 in the initial condition of the press 10 and closed when the top platen 16 is lowered relative to the bottom platen during the pressing portion of the operating cycle of the press 10.

As shown in FIG. 3, the top platen 16 is driven by the piston 116a of a piston-cylinder mechanism 116, and the end platen 20 is driven by the piston 120a of a piston-cylinder mechanism 120. Also, the side platen 22 is driven by the piston 122a of a piston-cylinder mechanism 122, and the side platen 24 is driven by the piston 124a of a piston-cylinder mechanism 124. Each piston-cylinder mechanism is hydraulically driven. In FIG. 3, each piston-cylinder mechanism is shown in the initial condition of the press 10.

When the hydraulic fluid pump 30 is operating, hydraulic fluid is pumped by the hydraulic fluid pump 30 from a tank to a pressure-relief valve 102, which preferably is a Vickers No. CG-lO-BVIO, and from the pressure-relief valve 102 both to a solenoid valve 104, of which the solenoid 88 is a part, and to a solenoid valve 106, of which the solenoid 84 is a part. The pressure-relief valve 102 opens to relieve pressure in excess of a preset pressure, e.g., 600 psig. and when open permits hydraulic fluid to flow to the tank 100. When the solenoid 88 is in its first position, as shown, hydraulic fluid flows through the solenoid valve 104 to the tank 100. When the solenoid 88 is in its second position, the flow of hydraulic fluid through the solenoid valve 104 to the tank 100 is blocked. When the solenoid 84 is in its first position, as shown, hydraulic fluid is directed both from the P-port of the solenoid valve to the A-port thereof and from the B-port thereof to the T-port thereof. When the solenoid 84 is in its second position, hydraulic fluid is directed both from the P-port of the solenoid valve 106 to the B-port of the solenoid valve 106 and from the A-port thereof to the T-port thereof.

When the hydraulic fluid pump 30 is operating, hydraulic fluid also is pumped by the hydraulic fluid pump 30 from the tank 100 through a check valve 110 to the P-port of a pilot-operated valve 112, which preferably is a Vickers No. DG-354-50. The T-port of the valve 112 is connected to the tank 100. The valve 112 is positionable between a first position and a second position and is arranged to be positioned in the first position when the hydraulic fluid pressure on the B side of the valve 112 exceeds the hydraulic fluid pressure on the A-side thereof and in the second position when the hydraulic fluid pressure on the A-side thereof exceeds the hydraulic fluidpressure on the B side thereof. When the valve 112is in the first position, as shown, hydraulic fluid is directed both from the P- port thereof to the B-port thereof and fromthe A-port thereofto the T-port thereof. When the valve 112\is in the second position, hydraulic fluid is directedboth from the P-port thereof ,to the A-port thereof and from the B-port thereof to the T-port thereof.

The pressure-relief valve 102 is connected tothe P port of the solenoid valve 106. The A-port of the solenoid valve 106 is connected to the A-sideof the pilotoperated valve 112. The B-port of the solenoid valve 106 is connected to the B-side of the valve 112.. Thus, the position of the valve 112 is responsive to the position of the solenoid 88. When the solenoid 881s positioned in its first position, as shown, the valve 112 is positioned in its first position, as shown. When the solenoid 88 is positioned in its second position, the valve 112 is positioned in its second position;

The A-port of the solenoid valve 106 also is connected to the A-port of the cylinder 12412 of the pistoncylinder mechanism 124. The B-port of the solenoid valve 106 also is connected to the B-port of the cylinder 124b. Thus, the position of the piston 124a is responsive to the position of the solenoid 84. When the solenoid 84 is in its first position, as shown, hydraulic fluid flows to the cylinder l24b such that thepiston 124a is retracted and the side platen 24 thus is lowered. When the solenoid 84 is in its second position, hydraulic fluid flows to the cylinder 124b such that the piston 1240 is extended and the. side platen 24 thus is raised.

The B-port of the pilot-operated valve 112 is connected to the A-port of thecylinder. 1201) of the pistoncylinder mechanism 120. The B-port of the cylinder 120k is connected, through a check valve 130 bypassing the valve 132 to be described and through a check valve 134 bypassing a valve 136 to be described, to the A-port of the pilot-operated valve 112. Thus, when the pilot-operated valve 112 is in its first position,

as shown, hydraulic fluid flows to the cylinder 12Gb such that the piston. 120a is retracted and the end platen 20 thus is removed relative to the end platen 18. i

The B-port of the pilot-operated valve 112 also is connected, through a check valve. 138* bypassing a valve 140 to be described, to the A-port of'the cylinder l16b of the piston-cylinder mechanism 116. The B-port of the cylinder l16b is connected, through a check valve 142 bypassing a valve 144 to be described, to the 6 A-port of the valve 112. Thus, when the pilot-operated valve 112 is in its first position, as shown, hydraulic fluid flows to the cylinder 1165 such that the piston 116a is retracted and the top platen 16 thus is raised relative to the bottom platen 14.

The B-port of the pilot-operated valve 112 also is connected, through a check valve 146 bypassing a valve 148 to be described, to the A-port of the cylinder 1221) of the piston-cylinder mechanism 122. The B-por t of the cylinder 1228 is connected, through the check valve 134 to the A-port of the pilot-operated valve 112. Thus, when the pilot-operated valve 112 is in its first position, as shown, hydraulic fluid flows to the cylinder l22b such that the piston 122a is withdrawn and the side platen 22 thus is withdrawn relative to the side platen 24.

When the pilot-operated valve 112 is positioned in the second position, hydraulic fluid flows from the A- port of the valve 112 through the check valve 142 bypassing the valve 144, to the B -port of the cylinder 116b. Thus, hydraulic fluid flows to the cylinder 11617 such that the piston 116a is extended and the top platen 16 thus is lowered relative to the bottom platen 14.

The valve 144, which preferably is a Vickers No. DT l5S2 O60-K-lO, is normally opened and arranged to be closed upon movement of the piston 116a nearly to its withdrawn position. The choke 162 is connected in parallel with the valve 144 to permit limited flow of hydraulic fluid when the valve 144 is closed. Thus, the valve 144 functions to decelerate the piston 116a upon movement of the piston 116a nearly to its extended position.

The valve 140 which preferably is a Vickers No. RCG-06-Zl-l 1, is normally closed and arranged to be opened uponapplication of hydraulic fluid pressure exceeding a preset pressure, e.g., psig. Thus, the

valve blocks extension of the piston 116a until such pressure exceeds the preset pressure. Also, because such pressure is less than the preset pressure when the hydraulic fluid pump 30 is not operating, the valve 140 then holds the piston 116a in its'witlidrawn position with the top platen 16 raised.

The valve 134, which preferably is part of a Vickers No. RCG- lO-A3-22, is normally closed and arranged to be opened upon application of hydraulic fluid pressure exceeding a preset pressure, e.g., 200 psigeThus, the

valve 134 limits the pressure applied by the top platen 16 to the belly being pressed. Also, when opened, the valve l34 permits hydraulic fluid to flow to the B-port of the cylinder 12% and thus effects extension of the piston 122a'and movement of the side platen 22 toward the side platen 24. A line 150 is connected from the valve 134 to apply an equal pressure to the B-port of the cylinder 1l6b. The equal pressure holds the belly being pressed while lateral pressure is being applied.

The valve 148, which preferably is a Vickers No. C- 714, is normally opened and arranged to be closed upon extension of the piston 122a to a predetermined position. When the valve 148 is closed, flow of hydraulic fluid from the A-port of the cylinder 12212 is blocked. Thus, the valve 148 controls extension of the piston 122a. As is known, thevalve 148 may be adjusted in relation to extension of the piston 122a for accomodation of bellies of different widths.

The valve 132, which preferably is a Vickers No. RCG-l-D2-22, is normally closed and arranged to be opened upon application of hydraulic fluid pressure exceeding a preset pressure, e.g., 500 psig. Thus, the valve 132 limits the pressure applied by the side platen 22 to the belly being pressed. Also, when opened, the valve 132 permits hydraulic fluid to flow to the B-port of the cylinder 120b and thus effects extension of the piston 120a and movement of the end platen toward the end platen 18.

A valve 152, which preferably is a Vickers No. CG- 06-B-10, is normally closed and arranged to be opened upon application of hydraulic pressure exceeding a preset pressure e.g., 450 psig. The valve 152, which is connected between the B-port of the cylinder 120b and the tank 100, is arranged to vent excess hydraulic fluid to the tank and thus to control the pressure applied to the piston 120a.

A pressure-sensitive switch 156, which preferably is a Barksdale No. 9048-2, also is connected to the B-port of the cylinder l20b. The switch 156 is normally closed and arranged to be opened, in response to the resulting back pressure, when extension of the piston 1200 is limited by contact with a belly being pressed.

Further details of structure and function in connection with the foregoing features of the hydraulic system of the bacon press 10 are not believed to be necessary for an understanding of this invention. Such details are believed to be within the scope of one skilled in the art and are omitted for sake of brevity.

As shown in FIG. 2, in order to provide for semi-automatic operation of the press 10, lines 44-5 and 44-7 respectively comprise ganged auto operation" switches, 200 and 202 respectively, arranged to be opened and closed manually. When the switches 200 and 202 are opened, lines 44-5 through 44-7 are disconnected from the network 44. Line 44-5 further comprises a lamp 204. When illuminated, the lamp 204 indicates semi-automatic operation of the press 10.

Line 44-6, which is connected to the switch 202 as shown, comprises a switch 206, which is normally opened and arranged to be closed at a predetermined point in the operating cycle of the press 10, and a lamp 208, which when illuminated indicates that the switch 206 is closed.

As shown in FIG. 3, the switch 206 is arranged to be closed upon extension of the piston 1160 to a predetermined position. Preferably, the switch 206 thus is arranged to be closed upon movement of the top platen 16 to a position where the top platen l6 and the side platen 24, together with the other platens, effectively block access from the exterior to the pressing chamber 12, in order to permit the operators hands to be removed from the handles 82 with comparative safety.

Line 44-7 further comprises, in series-connection, a normally closed emergency stop" switch 210, which is openable manually, a switch 212, which is ganged with the switch 206, a pair of contacts 214 of a time-delay relay, a pair of contacts 216 of a control relay, and the coil 218 of the control relay for the contacts 216. As described below, the contacts 214 are closed except when the coil of the time-delay relay is energized. The coil 218, which is connected (at 220) for energization through the switch 80, is connected in parallel with the solenoid 84. Also, through the switch 202, the series connection of the switches 210 and 212 and the contacts 214 and 216 is connected in parallel with the switch 80.

In line 44-7, the contacts 216 are arranged to be opened when the coil 218 is deenergized and closed when the coil 218 is energized. In operation, the contacts 214 are closed when the switch is closed. Also, once the switch 212 is closed together with the switch 206, the coil 218 and the solenoid 84 remain energized through the switches 202, 210 and 212 and the contacts 214 and 216, even if the switch 80 then is opened. Thus, the operating cycle of the press 10 continues to the end even if the operator then releases the handles 82.

Line 44-11 comprises the pressure-sensitive switch 156 (FIG. 3) and the coil 224 of the time-delay relay for the contacts 214. As mentioned, the switch 156 is normally closed and arranged to be opened, in response to the resulting back pressure, when extension of the piston a is limited by contact with a belly being pressed. The contacts 214 are normally closed and arranged to be opened after predetermined time delay, e.g., approximately from 0.2 to 0.5 seconds, when the coil 224 is energized through the switch 156. Thus, if the switch 80 is opened at the end of the operating cycle of the press 10, the coil 218 and the solenoid 84 are deenergized when the contacts 214 are opened.

Accordingly, in semi-automatic operation of the press 10, the operator is freed from having to hold the handles 82 during a major part, including the end, of the operating cycle of the press 10. However, for safety, the operator may be required to hold the handles 82 from initiation of the operating cycle of the press 10 by means of the handles 82 until the platens have moved to positions where they effectively block access from the exterior to the pressing chamber 12.

Thus, it will be appreciated that all of the recited objects, advantages and features of this invention have been demonstrated as obtainable in a highly practical apparatus and one that is simple and positive in operation. It will be further understood that although this invention has been described with respect to certain specific embodiments thereof, this invention is not limited thereto, since various modifications of said invention will suggest themselves fromthe aforesaid description and are intended to be encompassed within the scope of the appended claims wherein there is claimed.

We claim:

1. In a press of the type comprising a plurality of platens arranged for relative movement in orthogonal directions, each platen being arranged for movement between an initial position and a pressing position in accordance with an operating cycle of said press, said platens including a first and a second platen arranged for movement of said second platen toward and away from said first platen, a solenoid positionable between a first position and a second position and arranged to be positioned in said first position when deenergized and in said second position when energized, means for controlling relative movement of said platens during the operating cycle of said press such that said first platen moves away from said second platen and thus toward the initial position of said first platen when said solenoid is positioned in said first position and such that said first platen moves toward said second platen and thus toward the pressing position of said first platen when said solenoid is positioned in said second position, and an electrical circuit including a first switch and being adapted to connect said solenoid to a source of electrical power, whereby when said solenoid thus is connected to said source said solenoid is energized when said first switch is closed and deenergized when said first switch is opened, the improvement wherein said circuit includes a control relay having a coil connected in parallel with said solenoid, said control relay further having a pair of contacts arranged to be closed when said coil is energized and to be opened when said coil is deenergized, and a second switch arranged to be closed at a predetermined point in the operating cycle of said press, said second switch and said contacts being connected in series with each other and being connected in parallel with said first switch whereby said solenoid valve and said coil, once energized through said first switch means after said first switch has been closed and once said second switch has been closed, remains energized through said second switch and said contacts when said first switch is opened, said circuit further includes a third switch arranged to be closed at a predetermined point in the operating cycle of said press for a predetermined portion of the operating cycle of said press and to be opened otherwise, the point at which said third switch is arranged to be closed being later in the operating cycle of said press than the point at which said first switch is arranged to be closed, and a time-delay relay having a coil connected in series with the last-named switch, said time-delay relay having a pair of contacts connected in series both with said second switch and with the contacts of said control relay and arranged to be opened after a predetermined time-delay when the coil of said time-delay relay is energized and to be closed both when the coil of said time-delay relay is deenergized and during said prederermined time-delay, said third switch and the coil of said time delay relay being connected in parallel with said first switch and said solenoid.

2. The improvement of claim 1 wherein said third switch is arranged to be closed in response to contact of a third of said platens with material being pressed.

3. The improvement of claim 1 wherein said second switch is arranged to be closed upon movement of said second platen toward said first platen and past a predetermined point relative to said first platen.

4. The improvement of claim 3 wherein said third switch is arranged to be closed in response to contact of a third of said platens with material being pressed.

5. The improvement of claim 3 wherein said circuit further includes a normally closed switch connected in series with said second switch and the contacts of said control relay.

6. The improvement of claim 5 wherein said third switch is arranged to be closed in response to contact of a third of said platens with material being pressed.

22 3,3 a UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION ,I atent No. 3,727,545 Dated April 17, 1973 Inventor g Ditlev P. Madsen; Norman Rybicki It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected asshown below:

. Specification: I

Column 7, line 21, delete "closed" and insert open Column 7, lineZZ, delete "opened" and insert closed Column 8, line 18, delete "closed" and insert open 1 Column 8, line 18, delete "opened" and insert closed Claims: Column 8, line 57, delete ""seoond" and insert first Column 8, line 58, delete "first" and insert second Column 10, line 18, delete"'sacon.d" and insert first Column 10, line 18, delete "first" and insert second, Column 10, line 19, delete "first" 'and insertsecond Signed and sealed this 21st dayof May 1974.

LSEALl l Attest: EDWARD M. FLETCHER,JR. CQ'MARSHALL DANN- 1 Attestlng Officer 7 l 7 Commissioner of Pate'nts- 

1. In a press of the type comprising a plurality of platens arranged for relative movement in orthogonal directions, each platen being arranged for movement between an initial position and a pressing position in accordance with an operating cycle of said press, said platens including a first and a second platen arranged for movement of said second platen toward and away from said first platen, a solenoid positionable between a first position and a second position and arranged to be positioned in said first position when deenergized and in said second Position when energized, means for controlling relative movement of said platens during the operating cycle of said press such that said first platen moves away from said second platen and thus toward the initial position of said first platen when said solenoid is positioned in said first position and such that said first platen moves toward said second platen and thus toward the pressing position of said first platen when said solenoid is positioned in said second position, and an electrical circuit including a first switch and being adapted to connect said solenoid to a source of electrical power, whereby when said solenoid thus is connected to said source said solenoid is energized when said first switch is closed and deenergized when said first switch is opened, the improvement wherein said circuit includes a control relay having a coil connected in parallel with said solenoid, said control relay further having a pair of contacts arranged to be closed when said coil is energized and to be opened when said coil is deenergized, and a second switch arranged to be closed at a predetermined point in the operating cycle of said press, said second switch and said contacts being connected in series with each other and being connected in parallel with said first switch whereby said solenoid valve and said coil, once energized through said first switch means after said first switch has been closed and once said second switch has been closed, remains energized through said second switch and said contacts when said first switch is opened, and whereby said circuit further includes a third switch arranged to be closed at a predetermined point in the operating cycle of said press for a predetermined portion of the operating cycle of said press and to be opened otherwise, the point at which said third switch is arranged to be closed being later in the operating cycle of said press than the point at which said first switch is arranged to be closed, and a timedelay relay having a coil connected in series with the last-named switch, said time-delay relay having a pair of contacts connected in series both with said second switch and with the contacts of said control relay and arranged to be opened after a predetermined time-delay when the coil of said time-delay relay is energized and to be closed both when the coil of said timedelay relay is deenergized and during said prederermined timedelay, said third switch and the coil of said time-delay relay being connected in parallel with said first switch and said solenoid.
 2. The improvement of claim 1 wherein said third switch is arranged to be closed in response to contact of a third of said platens with material being pressed.
 3. The improvement of claim 1 wherein said second switch is arranged to be closed upon movement of said second platen toward said first platen and past a predetermined point relative to said first platen.
 4. The improvement of claim 3 wherein said third switch is arranged to be closed in response to contact of a third of said platens with material being pressed.
 5. The improvement of claim 3 wherein said circuit further includes a normally closed switch connected in series with said second switch and the contacts of said control relay.
 6. The improvement of claim 5 wherein said third switch is arranged to be closed in response to contact of a third of said platens with material being pressed. 